1. Field of the Invention
The present invention relates to an optical module. More particularly, the present invention relates to an optical module that reduces the size of a radiation member.
2. Description of the Related Art
As generally known in the art, electronic devices tend to incorporate more functions and become more complicated in this era of ubiquitous computing, and research has been conducted in connection with multi-channel optical modules for transmitting signals to share data or information between devices. Methods for transmitting large-capacity signals include utilizing multiplexing and/or increasing the modulation rate of a transceiver.
The realization of a high modulation rate generally has a number of technological or economical problems, and a multiplexing method is commonly used. As used herein, the modulate rate (or baud rate) is a rate type indicating an amount of information transmitted per unit time, and refers to the maximum number of modulations per second. Modules based on MMF (Multi-Mode Fiber) arrays have been proposed and are used to transmit large-capacity signals. Conventional optical modules include 12-channel transmitters and receivers, or may have respective 4-channel transceivers.
FIG. 1 is an illustration of a conventional optical module, which includes an MPO (Multi-Fiber Push On) connector 11 to be fastened to a multi-channel MMF; a PCB (not shown), a BGA (Ball Grid Array) connector 13 for facilitating electrical connection between the MPO connector 11 and the PCB; a FPCB (Flexible Printed Circuit Board) 14 for electrically connecting the BGA connector 13 to an IC (Integrated Circuit) 16; and a heat block 12 for emitting heat generated by the IC 16. The optical module 10 is mounted on the PCB (not shown). The MPO connector 11 has a high-density backplane for a communication system or data transmission, and a multi-fiber 15 provided on the PCB. The BGA connector 13 is positioned on the bottom of the heat block 12 to electrically connect to the IC 16 via the FPCB 14. Details regarding the BGA connector 13 is disclosed in Korean Patent Application No. 2005-0065516 (filed Jul. 19, 2005), entitled “BGA-TYPE CONNECTOR”, the disclosure of which will now be described briefly. The BGA connector has input/output ports at a predetermined interval in the horizontal and vertical directions to increase the number of signal input/output ports of the IC. The input/output ports of the BGA connector have solder balls to maintain electric and mechanical contact with the PCB. The number of solder balls of the BGA connector, which act as contacts, can be increased easily to provide signal input/output ports at a high density in a small area.
Still referring to FIG. 1, the IC 16 is positioned on the front surface of the heat block 12, which has an optical device mounting recess formed therein so that an optical device 15 extends from the rear surface of the MPO connector 11 to the heat block 12. The FPCB 14 is mounted between the rear surface of the MPO connector 12 and the front surface of the heat block 12.
The vertical front portion of the FPCB 14 is positioned between the rear surface of the MPO connector 11 and the front surface of the heat block 12, and the lower portion of the FPCB 14 is positioned between the bottom of the heat block 12 and the BGA connector 13. The FPCB 14 has an IC connection recess 17 formed on the front portion to electrically connect to the IC 16, which is positioned on the front surface of the heat block 12, and to electrically connect to the BGA connector 13, which is mounted on the bottom of the FPCB 14.
However, such a conventional optical module 10, as shown in FIG. 1, has a problem in that, since the BGA connector 13 is positioned on the bottom of the heat block 12, the heat block 12 must be at least long enough to mount the BGA connector 13. The size of the heat block thus increases the size of the optical module 10, which then occupies a great deal of space when mounted on the PCB and degrades the efficiency of the PCB. In addition, the size of the heat block 12, which must be large enough for mounting of the BGA connector, increases the cost of the optical module.